Ed,
I canot help very much. Out here, we get to fly with some of the best who can watch an airplane fly and give some suggestions on how to improve the thing. I am sort of spoiled with being able to share a flying field with at least one of those golden arms. However, I could suggest that you play around with leadout positions and tip weights, but you probably already know that and are doing so.
It took me more than a year to get my Bearcat to where it became a lot of fun and easy to fly. After you get some more time with yours, I am interested in how you feel about the Rabe rudder. I know many top fliers have tried it and have concluded that they do not need it. Indeed, there are outstanding pilots/airplanes that do not use it. My feeling is that there are no negative aspects to using it and that it can only help. (And no, I do not consider the added complexity, regardless of the system, nor the added weight to be negatives given the dividend of the system.)
I am able to essentially disengage my movable rudder and fly it in a fixed position.. I have done this several times over the years when the airplane has been in various stages of trim. After I got the movement down to what I have described, I can say that, at least for me, the rudder is a definite asset for this airplane.
By the way, your machine really looks good. Congratulations on a job well done.
Keith